Cairo-Bishop Criteria for Tumor Lysis Syndrome
The Cairo-Bishop criteria define tumor lysis syndrome (TLS) as either Laboratory TLS (LTLS) or Clinical TLS (CTLS), with LTLS requiring ≥2 abnormal metabolic values within 3 days before or 7 days after treatment initiation, and CTLS requiring LTLS plus significant clinical complications 1.
Laboratory TLS (LTLS)
LTLS is present when two or more of the following metabolic abnormalities occur:
- Uric acid: Above normal range OR 25% increase from baseline
- Potassium: Above normal range OR 25% increase from baseline
- Phosphate: Above normal range OR 25% increase from baseline
- Calcium: Below normal range OR 25% decrease from baseline
Critical timing window: These changes must occur within 3 days before or 7 days after initiation of cytoreductive therapy 1.
Key Improvement Over Prior Systems
The Cairo-Bishop criteria specifically addressed shortcomings of the earlier Hande-Garrow classification by:
- Accounting for patients with pre-existing abnormal baseline values (not just requiring 25% changes)
- Extending the monitoring window to include 3 days before treatment (capturing spontaneous TLS)
- Extending post-treatment monitoring to 7 days (not just 4 days) 1
Clinical TLS (CTLS)
CTLS requires the presence of LTLS plus one or more of these clinical complications:
- Renal insufficiency: Creatinine ≥1.5× upper limit of normal
- Cardiac arrhythmias or sudden death
- Seizures
Grading System
- LTLS: Present or absent (binary classification)
- CTLS: Graded by the maximal severity of the clinical manifestation present 1
Clinical Context and Timing
Most common presentation window: 12-72 hours after initiation of cytoreductive therapy, though symptoms can occur before chemotherapy starts 1.
Laboratory Values Associated with High Risk
Patients with uric acid ≥8 mg/dL have significantly higher risk (RR 4.03 compared to medium levels, RR 11.66 compared to low levels; P < .0001) 1.
Clinical Manifestations to Monitor
Beyond the core CTLS criteria, watch for:
- Nausea, vomiting, diarrhea, anorexia
- Lethargy, edema, fluid overload, hematuria
- Congestive heart failure, muscle cramps, tetany, syncope
- Possible sudden death 1
Cardiac Complications from Hyperkalemia
Elevated potassium produces arrhythmias, ventricular tachycardia, fibrillation, or cardiac arrest, plus neuromuscular effects including muscle cramps and paresthesia 1.
Common Pitfall
The Cairo-Bishop criteria are diagnosis-agnostic and apply uniformly to all patients—not just hematologic malignancies but also solid tumors 2, 3, 4. While TLS occurs most frequently in acute lymphoblastic leukemia and Burkitt's lymphoma, spontaneous TLS in solid tumors (particularly lung cancer) carries 63% mortality despite treatment 4.